FPSO's typically must perform the following functions: 1) primary separation of the well fluids (gases, solids, non-aqueous oil phase, aqueous phase), 2) secondary treatment of the separated phases for discharge or re-injection, and 3) storage of the produced oil until off-loading. Since the oil phase is the most valuable commodity, most of the FPSO's available hull space is dedicated to primary separation and storage of the produced oil. However, due to discharge permit restrictions for the aqueous phase, some of the FPSO's precious space must be allocated to water treatment equipment. Current FPSO's utilize the same Induced Gas Flotation vessels of either the vertical or horizontal configuration commonly found on fixed platforms and land-based treatment facilities. This equipment is designed to flocculate and float tiny oil droplets dispersed within the aqueous phase using gas bubbles and the addition of flocculating chemicals. The most common produced water treatment system designs are somewhat limiting for the FPSO application due to the space and weight limitations. Furthermore, the swaying nature of a floating ship makes conventional oil skimming and water level controls problematic.
What has been needed in the industry is a high-performance gas flotation separator system that can be incorporated into the existing hull tanks of an FPSO at a reasonable cost with limited deck space usage, and minimum height requirements.
What has also been needed in the industry is a high-performance gas flotation separator system that can be incorporated in a number of existing tank configurations (i.e., horizontal rectangular or cylindrical) with minimal internal modifications required and relatively simple construction. When incorporated into a used shipping container, for example, the method and device of the present invention would provide a highly cost-effective solution to portable gas flotation systems for use in oil/water spill clean-ups, plant capacity expansions, and temporary use systems.